Xeon 5500 with 2 DIMMs per channel at 1333 MHz

The integrated memory controller of the Intel Xeon 5500 series has some limitations: It runs at 1333 MHz with one DIMM per channel, it runs at 1033 MHz with two DIMMS per channels and with 800 MHz with 3 banks per channel. With Nehalem you can have either speed or memory size but not both. The limits are enforced by the system as soon as you put the DIMMS into the system. But the Sun X2270, x4170, x4270 x4275 and x6270 have a special capability. The systems were designed to enable a stable operation at 1333 MHz with 2 DIMMS per channel. The newest versions of the BIOS gives you the option to enable this mode of operation. You will find more informations about this in John´s blog article “Update to: Configuring and Optimizing Intel® Xeon Processor 5500 & 3500 Series (Nehalem-EP) Systems Memory”. The BIOS updates are available at www.sun.com (Sun Fire X4170/X4270/X4275 Software 2.0, Sun Blade X6270 Software 2.0 and Sun Fire X2270 2.0.0)